Tailstock for milling machines



April 24, 1945. E. MOEN 2,374,448

TAIL STOCK FOR MILLING MACHINES Filed March-ll, 19 45 I s Sheets-Sheet 1 VIII, 11/1/1i/7/7/1/1/11/111n 11111111 1111 Erick/ 10 e12) INVENTOR.

April 24, 1945. E. MOEN TAIL STOCK FOR MILLING MACHINES Filed Mafch 11, 1943 s Sheets- Sheet s III/I INVENTOR.

- and Patented Apr. 24, 1945 UNITED STATES PATENT OFFICE l TAILSTOCK FOR MILLING MACHINES Erick Moen, Detroit, Mich.

Application March 11, 1943, Serial No. 478,778

3 Claims.

My invention relates to: the tail stock covered in my Patent No. 2,242,978, dated May 20 1941, and also to a center pin installation for such tail stock covered in my Patent No. 2,265,568, dated December 9, 1941, and my main object is to provide a tail stock containing improvements over the patented structures.

Another object of my invention is to provide a number of features which make for the better construction of the tail stock, the improved control of its adjustment, and greater facility in the installation and handling of the tail stock.

With the above objects in view and any others which may suggest themselves from the description to follow, a better understanding of the invention may be had by reference to the accompanying drawings, in which- Fig. 1 is aside elevation of the improved tail stock, following the lines of Fig. l in either patent above referred to;

Fig. 2 is {a longitudinal section similar in its lower and right-hand portions to Fig. 2 in the earlier patent, and in its upper left-hand portion to Fig. 2 in the later patent;

Fig. 3 is a top planview of the tail stock similar to Fig. in the earlier patent;

Fig. 4 is a plan section'similar to Fig. 6 in, the earlier patent;

Fig. 5 is a rear view similar to Fig. 7 in the earlier patent;

Fig. 6 is a rear section similar to Fig. 3 in the earlier patent;

Fig. 7 is a section on the line 1-1 of Fig. 1;

Fig. 8 is a front view of the center pin installation similar to Fig. 4 in the later patent.

In a general sense, the improved tail stock embodies the construction of the earlier patent, and the center pin installation of the later one. Thus, reference to parts in these structures will be by means of numerals employed in the patents referred to. On the other hand, reference to new features will be made by means of other numerals.

Initially, one change is noted in the construction of the base I0. Whereas the same is made low at the rear only in the earlier patent, the numeral 90 in Fig. 1 shows that the frontal part of the improved base is also made low, to facilitate the application of short bolts to secure the base to the milling machine bed.

The second improvement resides in a change of the form and application of the bearing arch in the earlier patent. While such arch appears rounded and is secured by bolts 22, the

improved structure shows the counterpart of the arch 29 to be a keystone-shaped bearing standard 91 which is made separate from the base and welded to the same on a line 92, as suggested in Fig. 6, or made in one piece with the base Ill. The bearing standard is therefore more rigid; and the tapping of holes and use of fastening bolts is eliminated.

A further improvement resides in the locking of the feed screw I! of the earlier patent. Whereas this was doneby the provision of a collar 25 on the inner side of the screw shank and a receptacle 23 rising from the base ID, a more compact form of lock is employed in the improved structure, as illustrated in Figs. 4 and 6. Here it is seen that the shank of the feed screw I1 is annularly grooved at 93. A bolt 94 is screwed downwardly into the bearing standar 9| to seat in one side of the stem groove 93. Thus, the stem is locked from longitudinal motion; and the movement of the slide M can be brought much closer to the bearing standard than before. Incidentally, the head of the feed screw I1 is now square, as indicated at 95, for the application of a common wrench when the feed screw is to be operated. Also, the slide I4 is recessed in front, as indicated at 9511, to straddle the bearing standard when approaching the limit of its retraction and gain added movement.

Another improvement deals with the bolt 53 employed in the earlier patent to lock the slide [4 at any point in its movement. Provision is made in the newembodiment to lend the bolt a better hold and reduce the wear incident thereto. Thus,

" Figs. 4 and 6 show the application of a cold rolled steel plate 96 between the slide l4 and the base [0 at one side of the tail stock. The outer portion of the plate is secured to the base by means of a bolt 91 and lock washer 98, while the inner portion of the plate assumes a position under the lower end of the bolt 53. Such end is concaved as indicated at 99 to give it a sharp marginal edge. Thus, when the bolt is screwed down, its edge secures a sharp or cutting hold on the plate 96, such hold receiving a minimum amount of wear because of the hardness of the plate. It follows, therefore, that the plate may be used for a long time before it becomes so scored or worn that it will no longer offer a good hold for the bolt. In such event, it is an easy matter to remove the plate and to replace the same with a new one at nominal cost. It is preferable to employ a lock washer I00 under the head of the bolt 53.

It is also noted that the side keys 48 of the block 30 in the earlier patent are now replaced by two sets of side keys IBI occurring at the .ends

of the block, as clearly shown in Figs. 3 and 4. A double bearing is thus secured by the block. Incidentally, the Vertical bore in the block is moved floack from the center in the new embodiment, as noted in Fig. 2. This allows more stock in the front of the block to form a hearing or support for the reenter pin installation.

Another change occurs in the transmission of motion from the spindle M to the pin 46. Where as the spindle of the earlier patent has a worm thread 42 in mesh with a gear45 on the pin 46,-

the said thread and gear are now replaced by a pair of meshing spiral gears I02 which eliminate the need of threading the spindle ii. The latter is reduced in front as indicated at m3 to find a bearing in the end wall 35, as before, but to the rear of the gear 502 a reduction Hi l of the spindle receives a spacer sleeve 105. The knob 4B is securedto the rear end of the spindle by a crosspin 35a; and the knob is now formed with a square head N36 for the application of an ordinary wrench when the spindle 8! is to be operated.

The mounting of the center pin now employs the corresponding construction of the later patent,

and the structure of the tail stock is simplified for the adjustment of the center pin shaft 51. As noted in Fig. 2, the said shaft is not formed with a threaded extension, but is bored and tapped with a horizontal cavity from the rear to receive a screw 67 forming the frontal extension of a shank it having a knob I99v at its rear end. The shank i 98 is freely disposed in the tail stock, but means are provided to lock the shank against longitudinal motion as Well as to check it against rotation when it has once been adjusted. Thus, Fig. 2 shows that the shank W8 is made with an annular groove I Hi. The rear extension 64 of the tail stock receives a tapered. pin H! from the bottom, as shown in Fig. 7, the pin seating in one side of the groove l I!) and continuing upwardly in the form of a screw I I2 rising from the extension 5 3. This screw receives a wing nut l 13. Ordinarily, the pin Ill forms a lock to fix the shank I08 against longitudinal travel. However, after the knob I it has been rotated to adjust the center pin longitudinally, the tightening of the wing nut H3 draws upwardly on the pin Hi to wedge it in the side of the shank Hi8, also looking the same against rotary motion. Figs. 2 and 5 show that a crank handle I I4 is applied to the back of the knob lBQr by means of a pair of screws H5 in the event that it is difiicult to turn the knob H39. However, the crank handle may be removed or dispersed with in case this difii culty does not occur.

It will be evident from the above description that the salient features of the tail stock remain as before, but that they carry improvements which make for greater stability or strength of the tail stock, easier operation of its working parts, smoother adjusting action and greater simplicity.

I claim:

1. In a milling machine tail stock, a top bearing, a center pin longitudinally adjustable in the bearing and having a rear portion horizontally tapped to serve as a traveling nut, a screw rotatable in the latter, a shank for the screw in the rear end of the bearing, a head carried by the shank'rearwardly of the bearing, and. means co-operative with the shank to lock the same against longitudinal and rotary, motion, said means comprising an annular groove in the shank, a locking pin disposed in the bearing alongside the shank and seating tangentially in said groove, said locking pin being tapered, and means to draw on the locking pin to wedge it tightly in the groove.

2. In amilling machine'tail stock, a top bearing, a center pin longitudinally adjustable in the bearing and having a rear portion horizontally tapped to serve as a travelingnut, a screw rotat-.

able in the latter, a shank for the screw in the rear end of the bearing, a head carried by the shank rearwardly of the bearing, and means co-operative with the shank to lock the same against longitudinal and rotary motion, said means comprising an annular groove of partciroular cross-section in the shank, a locking pin disposed in the, bearing alongside the shank and seating tangentially in said groove, said locking pin being conically tapered, and means'to draw on the locking pin to wedge it tightly in the groove. 1

3. In a milling machine tail stock, a topbearing, a center pin longitudinally adjustable in the bearing and having a rear portion horizontally .tapped to serve as a traveling nut, a screw ro- ERICK MOEN. 

